This application relates to pneumatic tools and, in particular, to control mechanisms therefore. The application relates specifically to shutoff mechanisms for disconnecting a pneumatic motor from a supply of pressurized pneumatic fluid.
Pneumatically operated tools of varying types are known, including a wide variety of pneumatically-operated hand tools. Many such tools are designed for torque application to a workpiece and may include devices such as screw or nut driving tools, impact wrenches and the like. Such tools are typically provided with a trigger valve mechanism to manually control the flow of pressurized pneumatic fluid, typically air, to an air motor. Some pneumatic tools are also provided with automatic shutoff mechanisms, responsive to a particular event or condition, such as the application of a predetermined torque level. Such prior shutoff arrangements have typically been rather complex, bulky, expensive, relative slow acting and/or difficult to adjust.